Power driven pipe machine



Dec. 12, 1961 B. G. BJALME 3,012,792

POWER DRIVEN PIPE MACHINE Filed Feb. 17, 1960 2 Sheets-Sheet 1 I 40 I Jjfilf 5 F LL 57 35 35 6 4/ w /4 1 Q 37 I 35 5 91 37 FIG. 4 /5 4 13 2? I25 v /7 be 22 5:7

FICaJ 2/ INVENTOR.

Dec. 12, 1961 B. G. BJALME POWER DRIVEN PIPE MACHINE 2 Sheets-Sheet 2Filed Feb. 17, 1960 IN E EN TOR. m.

United States Patentfiice Patented Dec. 12, 196 1 3,012,792 POWER DRIVENPIPE MACHINE Bengt G. Bjalme, Erie, Pa., assignor to Reed ManufacturingCompany, Erie, Pa., a corporation of Pennsylvania Filed Feb. 17, 1960,Ser. No. 9,267 Claims. (Cl. 279--114) This invention is a power drivenpipe machine having torque energized pipe gripping jaws providing acontrolled relation between the driving torque and the force with whichthe pipe is gripped.

In the drawing, FIG. 1 is a sectional side elevation, FIG.

21's a front view partly broken away, FIGS. 3 and 4 are views fromopposite ends of the jaws, FIG. 5 is a section on line 5-5 of FIG. 1 andFIG. 6 is a section on line 6-6 of FIG. 2.

The machine has a frame 1 having on its under side sockets 2, 3 forfront legs 4 and a socket 5 for a rear leg 6 providing a stable threepoint support for the machine. On the rear of the frame is a motor 7which drives a pinion 8 through reduction gearing 9. The pinion mesheswith a gear 10 journaled on the frame by bearings 11, 12.

On the rear side of the gear 10 is fixed a pipe guide body 13 in thefree end of which is screwed a guide plate 14 having radial slots 15carrying pipe guide members 16. The guide members are moved in and outby a manually turned scroll plate 17.

On the front side on the gear 10 is bolted a drive plate 13. Between thedrive plate and the gear is a scroll carrier 19 journaled on a shoulder20 on the gear 10. On the scroll carrier are fiXed three symmetricallyspaced segments 21 having an annular groove 22 therein rotatablyreceiving a scroll 23. The scroll is turned by a hand wheel 24 havingthree arcuate recesses 25 therein each receiving a projection 26 on thescroll. There is a lost motion between the recesses and the projectionsso that the hand wheel can impart a hammer blow to the scroll.

The scroll carrier 19 is connected to the drive plate 18 by three coilsprings 27 arranged in semi-cylindrical sockets 28, 29 respectively inthe drive plate 18 and in each of the segments 21 fixed to the scrollcarrier. The sockets 28, 29 have semi-circular end surfaces or seats 30,31 which confine the springs. In the neutral or non-driving position,the seats 30, 31 are in alignment. Upon relative rotation of the driveplate 18 with respect to the scroll carrier 19 in either direction, thesprings 27 are compressed between the end surfaces 30, 31. The springs27 form a resilient driving connection from the drive plate 13 to thescroll carrier.

The sides of the segments 21 are spaced from each other and are undercutat 32 to provide a radial slot or guideway 33 between each pair ofsegments slidably receiving a jaw carrier 34-. On the face of the jawcarriers adjacent the scroll plate are teeth 35 which fit between theusual ribs 36 of the scroll plate. As the scroll plate is turnedrelative to the jaw carriers 34, the jaw carriers are moved radially inor out, depending on the direction of relative motion. On the face ofeach jaw carrier, remote from the scroll plate, is a pin 37 on which ispivoted a jaw 38 having at its inner end a toothed surface 39 forengaging the pipe and at its outer end a pin 40 rotatably received in ablock 41 slidably in a radial guideway 42 in the drive plate 18. Thepins 37 and 40 are radially spaced from each other so that as the driveplate 18 turns relative to the scroll carrier 19, the jaws are pivotedabout the pins 37 by a force a lied to the pin 40. This applies agripping force proportional to the amount of pivotal movement of the jawabout the pivot pin 37. This additional force prevents slipping of thepipe under heavy load.

The gripping force of the jaws 38 on the pipe is made up of twocomponents. First, there is the gripping force imparted by thetightening of the jaws 38 against the pipe by the hand wheel 24. Thisgripping force is substantial due to the gradual pitch of the scroll andis augmented by the hammer blow effect made possible by the clearancebetween the recesses 25 and the projections 26 on the scroll plate. Thesecond component of the gripping force is proportional to the drivingtorque imparted to the drive plate 18 from the motor through the gear10. Since this component of the gripping force is proportional to thedriving torque, it increases with the torque and thereby preventsslippage of the pipe during heavy load.

The magnitude of the torque energized component of the pipe grippingforce is controlled in part by the stiifness of the springs 27 and inpart by the radial spacing of the pivot pins 37 and 4d. If the springs27 were absolutely rigid, no relative movement between the drive plate18 and the segments 21 could take place and there would be no additionalpipe gripping force due to the driving torque. The torque energizedcomponent is limited to a safe value by projections 43 on the driveplate 18 received between stops 44 in the faces of the segmentszl'adjacent the drive plate. In the unlocked position of the jaws, thereis a clearance 45 between each end of the projections 43 and theadjacent stop 44. The clearance 45 is such that it is taken up when thejaws have pivoted the allowable amount. After take up of the clearance,the drive plate and scroll carrier are driven together without furtherrelative rotation and the torque energized component of the grippingforce does not increase with further increase in driving torque.

When the driving torque is released, the torque energized component ofthe gripping force disappears and the jaws may be easily unlocked fromthe pipe. The forces stored in the springs 27 assist in unlocking thejaws and return the jaws to the central positions.

In the use of the machine, the pipe is inserted through the guides 16until the desired portion of the pipe comes opposite the toothedgripping surfaces 39 of the jaws. The guide fingers are manuallytightened against the pipe by turning the guide scroll 17 therebysteadying the pipe in the guide body 13. The jaws 38 are manually movedagainst the pipe by turning the hand wheel 24. A considerable grippingforce is exerted by the jaws due to the very gradual pitch of the scroll36 and to the supplemental hammer blow eifect. The pipe tool is thenapplied to the pipe and the motor 7 is started. The pipe tool, whichmay, for example, be a pipe threader, requires a considerable torque. Itis held stationary, for example by a suitable stop on the frame of themachine, and the pipe is turned by the gear 10. The guide body 13 turnswith the gear so there is no relative rotation between the pipe and theguide members 16. However, resistance to turning of the pipe relative tothe pipe tool results in a retarding force at the toothed surfaces 39 ofthe jaws which causes relative rotation between the drive plate 18 andthe segments 21 resulting in a compression of the springs 27, producinga relative movement between the drive plate 18 fixed to the gear 10 andthe segments 21 between which the jaw carriers 34 are guided. Therelative movement causes the jaws 38 to pivot about pins or fulcrums 37on the jaw carrier 34 and to force the teeth against the pipe with aforce proportional to such movement. At the end of the operation, themotor is stopped and the jaws unlocked by the hand wheel 24 assisted bythe springs 27. The hammer blow effect is available to assist inunlocking the jaws. The jaws are easy to lock in non slipping engagementwith the pipe, even under the heaviest loads, and are equally easy tounlock.

What is claimed as new is:

1. In a power driven pipe machine, a driving member, a driven memberrotatable relative to the driving member, spring means for yieldablyresisting relative rotation between the members, a scroll platerotatably carried on the driven member, a radially extending guide inthe driven member, a jaw carrier in said guide having teeth engaging thescroll to move the jaw carrier radially as the scroll is rotatedrelative to the driven member, a jaw having a pipe engaging surface, afulcrum for the jaw on the jaw carrier spaced from the pipe engagingsurface, and a connection between the jaw and the driving memberradially spaced from the fulcrum and from the pipe engaging surface forpivoting the jaw about the fulcrum in proportion to the relativerotation between the members.

2. Ina power driven pipe machine, a driving member, a driven member anda scroll member rotatable relative to each other, spring means foryieldably resisting relative rotation between the driving and drivenmembers, a radially extending guide, a jaw carrier in said guide havingteeth engaging the scroll member to move the jaw carrier radially as thescroll member is rotated relative to the guide, a jaw, a fulcrum on thejaw carrier for the jaw, and means for pivoting the jaw about thefulcrum in proportion to the relative rotation between the driving anddriven members.

3. In a power driven pipe machine, a driving member, a driven member anda scroll member rotatable relative to each other, opposed tangentiallydirected spring seats on the driving and driven members, a compressionspring between said seats yieldably resisting relative rotation betweenthe driving and driven members, a radially extending guide, a jawcarrier in said guide having teeth engaging the scroll member to movethe jaw carrier radially as the scroll member is rotated relative to theguide, a jaw, a fulcrum on the jaw carrier for the jaw,

and means for pivoting the jaw about the fulcrum in proportion to therelative rotation between the driving and driven members.

4. In a power driven pipe machine, a radially extending guide, a scrollmember rotatable relative to the guide, a jaw carrier in said guidehaving teeth engaging the scroll to move the jaw carrier radially as thescroll is rotated relative to the guide, a jaw having a pipe engagingsurface, a fulcrum for the jaw on the jaw carrier spaced from the pipeengaging surface, a connection to the jaw radially spaced from thefulcrum and from the pipe engaging surface, and means for applying aforce to said connection proportional to the torque load on the aws.

5. In a power driven pipe machine, a driving member, a driven memberrotatable relative to the driving member, cooperating normallydisengaged stop means on said driving and driven members coming intoengagement upon a predetermined relative rotation between said membersto limit such relative rotation, a scroll plate rotatably carried on thedriven member, a radially extending guidc in the driven member, a jawcarrier in said guide having teeth engaging the scroll to move the jawcarrier radially as the scroll is rotated relative to the driven member,a jaw having a pipe engaging surface, a fulcrum for the jaw on the jawcarrier spaced from the pipe engaging surface, and a connection betweenthe jaw and the driving member radially spaced from the fulcrum and fromthe pipe engaging surface for pivoting the jaw about the fulcrum inproportion to the relative rotation between the members.

References Cited in the file of this patent UNITED STATES PATENTS

